The long term goal of this research is to understand the structure and function of androgen receptors in the male hormone sensitive organs and cells. The specific aims in the next several years are: I. Preparation of specific anti-androgen receptor antibodies by lymphocyte transformation and hybridoma technology and/or by epitope selection methods. II. Cloning of androgen receptor cDNA by using expression libraries and antibody screening techniques, structural analysis of cDNA, and study of the regulation of the expression of androgen receptor gene in target organs. III. Cellular and intracellular localization, and structural analysis of androgen receptors by immunochemical analysis. Monoclonal antibodies and cDNA for androgen receptors may be used in the characterization of androgen receptors and its regulation in the abnormal organs and in the study of their roles in causing or in the progression of diseases such as benign prostate hyperplasia or prostate cancers.